How to disable mat text box filed in angular

 How to disable mat form filed in angular.

isDisableField: boolean = true;

In html need add [readonly] = "isDisableField"

in CSS: 

.disable-field {

pointer-events: none;

.mat-form-field-flex {

background--color: gray;

}

.mat-form-field-outline {

display : none;

}

}